The present invention relates to a single lens reflex camera capable of continuous photographing, particularly enabling high speed continuous photography by means of an automatic winding up device.
Many single lens reflex camera capable of continuous photographing by mounting the automatic winding up device have been proposed. With respect to this kind of camera, the time needed for taking one photograph at the time of continuous photographing depends upon the time during which the automatic winding up device completes the camera winding up and the shutter is released and the time during which, after the shutter release the winding up operation for the next photographing starts. Considering these time periods, the time commencing with the start of winding up until the shutter release depends upon the work of the camera driven by means of the winding up mechanism, namely, the winding up moment and the rotation angle. The work is divided in the film feeding, the shutter winding up, the mirror operation and the diaphragm mechanism setting. Further, the time from the camera release until the start of the next winding up operation is the addition of the operation time of the diaphragm operation mechanism and the mirror operation time after the shutter release, the running time of the shutter curtain, the shutter time forming time and so on. Depending upon the kind of camera the stabilizing time for the stopped mechanism for the diaphragm and the mirror, the information memorizing time for the automatic exposure and so on add to the above time.
Consequently, in order to shorten the time needed for one photograph at the time of the continuous photographing with the automatic winding up device so as to enable the high speed continuous photography, it is necessary to provide a means for shortening the previously mentioned times, whereby in the case of the high speed photography it is effective to adopt the photographic mode in which the diaphragm operation and the mirror operation are excluded. In this way, the work of the automatic winding up device will be only the film feeding and the shutter winding up, so that the time needed for taking a photograph can be shortened. Further, considering the operation times after the shutter release, the time needed for the diaphragm operation and that for the shutter operation are comparatively long with reference to the running time of the shutter curtain in the case of the short shutter time, it is possible to shorten the operation time after the shutter release by adopting the photographic mode in which the above mentioned operations are eliminated.
A camera whose diaphragm operation mechanism and the mirror operation mechanism are omitted so as to enable high speed continuous photography has been proposed. Namely, in the case of this kind of camera, a fixed mirror is adopted instead of the totally reflecting movable mirror necessary for the single reflex camera. A fixed half-permeable mirror is used, while the diaphragm is manually set and locked so as to carry out high speed continuous photographing. By means of this kind of camera, high speed photographing of as many as 9 pictures a second is possible. Because the fixed half-permeable mirror is used, the amount of the light into the view finder is not so great so that the range finding is difficult, which is inconvenient. In other words, the camera is convenient for special application but inconvenient for ordinary photography, namely for the ordinary and the low speed continuous photography.
Since the camera is not only convenient for ordinary photographing but is also capable of high speed continuous photographing is contemplated a camera, which is provided with a photographic mode change over mechanism designed in such a manner that the ordinary diaphragm operation as well as the ordinary mirror operation are carried out in the case of ordinary photography by means of the manual winding up or the low speed automatic winding up while both of the mechanisms are made inoperable only in the case of the high speed continuous photographing. For this purpose, either the method in accordance with which the totally reflecting movable mirror to be used in the case of ordinary photographing is replaced with the fixed mirror and the diaphragm is manually set and locked in the case of the high speed continuous photographing, or the method in accordance with which the photograph is taken after the scene has been determined, with the camera being fixed on a tripod or the like, the mirror manually lifted up and the diaphragm manually set and locked. However, in many cases very high speed continuous photographing is needed, quick and sure operability are required so that the above methods lack practicability.